The present invention relates to a method for feeding a specific boron compound to a reactor, a boron compound having a controlled particle diameter useful as a component of a catalyst for polymerization of an olefin and a method for producing the same. More particularly, it relates to a method for continuously feeding a boron compound useful as a component of a catalyst for polymerization of an olefin to a reactor, particularly an apparatus for preparing a catalyst or a reactor for polymerization of an olefin, said boron compound having a controlled particle diameter, and a method for producing said boron compound.
Many reports have already been presented on methods for producing olefin polymers with catalysts for olefin polymerization, which uses a transition metal compound (e.g. a metallocene complex or non-metallocene complex) and a specific boron compound. Said boron compound, which is also commercially available in recent years, is usually solid containing large size particles having a particle diameter of several hundreds micrometers to several millimeters, and while it is soluble in toluene to some extent, it has a low solubility in most solvents including saturated hydrocarbons. Therefore, conventionally it has been used in a solution having not so high concentration or used by adding undissolved part of said boron compound remaining in solid form into a vessel.
For example, In Japanese Patent Publication (Kohyo) No. Hei 1-502036 discloses a method for producing an olefin polymer in which tri-n-butylammonium tetrakis(phenyl)borate is suspended in toluene, bis(pentamethylcyclopentadienyl) zirconium dimethyl is added thereto, Cp*2Zr(C6H4)B(C6H5)3  less than  less than wherein Cp* represents xcex75-pentamethylcyclopentadienyl group greater than  greater than  is isolated and used as a catalyst for polymerization of an olefin. In this method, tri-n-butylammonium tetrakis(phenyl)borate is provided in advance in the form of a suspension in toluene in a reactor for preparing a catalyst, and the catalyst is prepared by adding a metallocene complex thereto.
In addition, in U.S. Pat. No. 5,408,017, it is disclosed that a method for producing an olefin polymer in a high-pressure polymerization apparatus at 1,300 bar, in which method N,N-dimethylanilnium tetrakis(pentafluorophenyl)borate and dimethylsilylbis(4,5,6,7-tetrahydroindenyl) zirconium dimethyl are mixed in toluene to prepare a homogeneous catalyst solution, which is used as a catalyst for polymerization of an olefin. In this method, while a solid N,N-dimethylanilnium tetrakis(pentafluorophenyl)borate is used for the preparation of the catalyst, a homogeneous catalyst solution is provided before use for polymerization by mixing it with the metallocene complex in toluene, and then said solution is continuously fed to a polymerization reactor with a high-pressure pump.
Furthermore, Japanese Patent Publication (Kokai) No. Hei 7-157508 discloses a method in which a solution of triisobutyl aluminum in toluene is added to a solution of diphenylmethylene (cyclopentadienyl) (fluorenyl) zirconium dichloride in toluene in a separate vessel before use for polymerization, and further, a solution of N,N-dimethylanilnium tetrakis(pentafluorophenyl)borate in toluene is added to obtain a homogeneous catalyst solution, then said solution is fed to a high-temperature high-pressure polymerization reactor.
Conventionally, as described above, when said boron compound is continuously fed to a reactor, a discontinuous procedure for preparing a homogeneous catalyst solution in a separate vessel, was adopted or a solution having not so high concentration was used.
In Published Specification No. WO94/00459, there is described a method for producing said boron compound and a method for purifying a produced crude boron compound that is colored. According to said method for purification, a method is disclosed in which the produced crude boron compound dissolved in ethers, alcohols, ketones or halogenated aliphatic hydrocarbons as a solvent is precipitated by water or an aliphatic hydrocarbon solvent, but there is no description for particle diameter of the obtained boron compound.
In view of these circumstances, the problem to be solved by the present invention, in other words, the purpose of the present invention is to provide a method capable of feeding a boron compound useful as a catalyst component for polymerization of an olefin continuously and in large amount to a reactor, and additionally, to provide a boron compound capable of allowing steady feed thereof without using it in the state of a solution and allowing stable operation of a feeding apparatus, when used as a catalyst component for polymerization of olefin or the like, and to provide a method for producing said boron compound.
Namely, the present invention relates to a method for feeding a boron compound, which comprises feeding at least one boron compound selected from (1) to (3) described below in the state suspended or slurried in a solvent continuously to a reactor; a boron compound in the form of fine particles having a maximum particle diameter of 50 xcexcm or less comprising one or more boron compounds selected from (1) to (3) described below; a catalyst component for olefin polymerization consisting of said boron compound in the form of fine particles; a method for producing a boron compound in the form of fine particles which comprises dissolving one or more boron compounds selected from (1) to (3) described below in an aromatic hydrocarbon solvent and then precipitating in an aliphatic hydrocarbon solvent; and a method for producing boron compound in the form of fine particles, which comprises pulverizing one or more boron compounds selected from (1) to (3) described below so that their maximum particle diameter is 50 xcexcm or less.
(1) a boron compound represented by the general formula: BQ1Q2Q3,
(2) a boron compound represented by the general formula: G+(BQ1Q2Q3Q4)xe2x88x92, and
(3) a boron compound represented by the general formula: (L-H)+(BQ1Q2Q3Q4)xe2x88x92
(in each of the above general formulae, B is a boron atom in the trivalent valence state, Q1 to Q4 are a halogen atom, a hydrocarbon group, a halogenated hydrocarbon group, a substituted silyl group, an alkoxy group or a di-substituted amino group, which may be the same or different, respectively. G+ is an inorganic or organic cation, L is a neutral Lewis base, and (L-H)+ is a Brxc3x8nsted acid.)
The present invention is described below in more detail.
The boron compound used in the present invention is at least one boron compound selected from (1) to (3) described below.
(1) a boron compound represented by the general formula: BQ1Q2Q3,
(2) a boron compound represented by the general formula: G+(BQ1Q2Q3Q4)xe2x88x92, and
(3) a boron compound represented by the general formula: (L-H)+(BQ1Q2Q3Q4)xe2x88x92
(in each of the above general formulae, B is a boron atom in the trivalent valence state, Q1 to Q4 are a halogen atom, a hydrocarbon group, a halogenated hydrocarbon group, a substituted silyl group, an alkoxy group or a di-substituted amino group, which may be the same or different, respectively. G+ is an inorganic or organic cation, L is a neutral Lewis base, and (L-H)+ is a Brxc3x8nsted acid.)
In the boron compound (1) represented by the general formula: BQ1Q2Q3, B is a boron atom in the trivalent valence state, Q1 to Q3 are a halogen atom, a hydrocarbon group, a halogenated hydrocarbon group, a substituted silyl group, an alkoxy group or a di-substituted amino group, which may be the same or different, respectively. Q1 to Q3 are preferably a halogen atom, a hydrocarbon group containing 1-20 carbon atoms, a halogenated hydrocarbon group containing 1 to 20 carbon atoms (for example, a fluorinated aryl group of 6 to 20 carbon atoms containing at least one fluorine atom being preferred), a substituted silyl group containing 1 to 20 carbon atoms, an alkoxy group containing 1 to 20 carbon atoms or an amino group containing 2 to 20 carbon atoms, and more preferred Q1 to Q3 are a halogen atom, a hydrocarbon group containing 1 to 20 carbon atoms, or a halogenated hydrocarbon group containing 1 to 20 carbon atoms.
Specific examples of the boron compound (1) represented by the general formula: BQ1Q2Q3 include tris(pentafluorophenyl)borane, tris(2,3,5,6-tetrafluorophenyl)borane, tris(2,3,4,5-tetrafluorophenyl)borane, tris(3,4,5-trifluorophenyl)borane, tris(2,3,4-trifluorophenyl)borane, phenylbis(pentafluorophenyl)borane and the like, with tris(pentafluorophenyl)borane being the most preferred.
In the boron compound (2) represented by the general formula: G+(BQ1Q2Q3Q4), G+ is an inorganic or organic cation, B is a boron atom in the trivalent valence state, and Q1-Q4 is the same as Q1 to Q3 described in (1) above.
In specific examples of the boron compound (2) represented by the general formula: G+ (BQ1Q2Q3Q4)xe2x88x92, inorganic cations as G+ include ferrocenium cation, alkyl-substituted ferrocenium cation, silver cation and the like, and organic cations as G+ include triphenylmethyl cation and the like. Particularly preferred one as G+ is carbenium cation and the most preferred one is triphenylmethyl cation. (BQ1Q2Q3Q4)xe2x88x92 includes tetrakis(pentafluorophenyl)borate, tetrakis(2,3,5,6-tetrafluorophenyl)borate, tetrakis(2,3,4,5-tetrafluorophenyl)borate, tetrakis(3,4,5-trifluorophenyl)borate, tetrakis(2,3,4-trifluorophenyl)borate, phenyltris(pentafluorophenyl)borate, tetrakis(3,5-bistrifluoromethylphenyl)borate and the like.
Specific combinations of them include ferrocenium tetrakis(pentafluorophenyl)borate, 1,1xe2x80x2-dimethylferrocenium tetrakis(pentafluorophenyl)borate, silver tetrakis (pentafluorophenyl) borate, triphenylmethyl tetrakis(pentafluorophenyl)borate, triphenylmethyl tetrakis(3,5-bistrifluoromethylphenyl)borate and the like, and triphenylmethyl tetrakis(pentafluorophenyl) borate is most preferable.
In the boron compound (3) represented by the general formula: (L-H)+(BQ1Q2Q3Q4)xe2x88x92, L is a neutral Lewis base, (L-H)+ is a Brxc3x8nsted acid, B is a boron atom in the trivalent valence state, and Q1 to Q4 is the same as Q1 to Q3 described in (1) above.
In specific examples of the boron compound (3) represented by the general formula: (L-H)+(BQ1Q2Q3Q4)xe2x88x92, (L-H)+ as the Brxc3x8nsted acid includes trialkyl-substituted ammonium, N,N-dialkylanilinium, dialkylammonium, triarylphosphonium and the like, and (BQ1Q2Q3Q4)xe2x88x92 includes those mentioned above.
Specific combinations thereof include triethylammonium tetrakis(pentafluorophenyl)borate, tripropylammonium tetrakis(pentafluorophenyl)borate, tri-n-butylammonium tetrakis(pentafluorophenyl)borate, tri(n-butyl)ammonium tetrakis (3,5-bistrifluoromethylphenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, N,N-diethylanilinium tetrakis(pentafluorophenyl)borate, N,N-2,4,6-pentamethylanilinium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(3,5-bistrifluoromethylphenyl)borate, diisopropylammonium tetrakis(pentafluorophenyl)borate, dicyclohexylammonium tetrakis(pentafluorophenyl)borate, triphenylphosphonium tetrakis(pentafluorophenyl)borate, tri(methylphenyl)phosphonium tetrakis(pentafluorophenyl) borate, tri(dimethylphenyl)phosphonium tetrakis (pentafluorophenyl)borate and the like, and tri-n-butylammonium tetrakis(pentafluorophenyl)borate or N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate is most preferable.
The boron compound used in the present invention is preferably the boron compounds of (2) or (3) described above and in particular preferably triphenylmethyl tetrakis(pentafluorophenyl)borate and N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate. Most preferably, it is N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate.
In the present invention, the above described boron compound is used in the state suspended or slurried in a solvent. The state suspended or slurried in a solvent referred to in the present invention means the state in which solids are not completely dissolved in the solvent and solid particles are dispersed in the solvent. In the present invention, the state of suspension and the state of slurry are not particularly distinguished.
In the present invention, when the above described boron compound is fed in the state of which the boron compound is suspended or slurried in a solvent, it is preferred that the sedimentation velocity of said boron compound in the suspended or slurried state is lower than the flow velocity in the pipeline in order that, for example, said boron compound does not deposit in the pipeline.
In the present invention, the solvent used for suspending or slurrying is not particularly limited insofar as it does not cause problems in the use of the boron compounds, and hydrocarbon solvents are preferably used.
As the hydrocarbon solvents, either saturated hydrocarbon solvents or aromatic hydrocarbon solvents may be used, but saturated hydrocarbon solvents are preferred from the viewpoint of problems such as offensive smell, in the field of polymerization of olefins. The saturated hydrocarbon solvents include butane, hexane, heptane, octane, cyclohexane, dodecane, liquid paraffin and the like, and the aromatic hydrocarbon solvents include benzene, toluene, xylene and the like.
In the present invention, it is preferred to use a solvent having a high viscosity in order that the sedimentation velocity of said boron compound in the suspended or slurried state is lower than the flow velocity in the pipeline. The viscosity of the solvent is preferably 0.8 cp (centipoise) or more, more preferably 1.4-1200 cp, most preferably 1.6-50 cp.
Specific examples of solvents having a high viscosity include dodecane, various liquid paraffins, mixed solvents of these with other solvents and the like. As the liquid paraffins, for example, commercially available liquid paraffins having various viscosities within about 2 to about 2000 cp can be used. The viscosity referred to herein means the viscosity at 20xc2x0 C.
When a pipeline is used in the feeding method of the present invention, the diameter of the pipeline is not particularly limited and is 0.5 to 100 mm, preferably 1 to 50 mm and more preferably 1.5 to 30 mm.
In the present invention, there is no particular limitation in the ratio between the amount to be used of the boron compound in the state of which said boron compound is suspended or slurried in a solvent and that of the solvent. While the above described boron compound is soluble to some extent in the aromatic hydrocarbon solvent such as toluene, according to the present invention in which the undissolved part is used in the suspended or slurried state, it is possible to feed a large amount of the boron compound in smaller volume. In addition, while the above described boron compound has a low solubility in the saturated hydrocarbon solvent and said boron compound contained in the solution are small in amount, according to the present invention, it is possible to feed a large amount of said boron compound in smaller volume.
When an aromatic hydrocarbon solvent is used, it is possible to feed in the ratio between the above described boron compound and the solvent, represented by a molar number of the boron compound to the volume of the solvent, of 2-800 millimoles/liter, and it is possible to feed more preferably in 6-500 millimoles/liter and further preferably 10-300 millimoles/liter. When a saturated hydrocarbon solvent is used, it is possible to feed in the ratio of 0.0001-800 millimoles/liter, and it is possible to feed more preferably in 0.001-500 millimoles/liter.
In the present invention, the above described boron compound is continuously fed to a reactor in the state of which the boron compound is suspended or slurried in a solvent.
The reactor herein refers to an apparatus subjected to the reaction using the above described boron compound, and include, for example, catalyst preparation apparatuses in which the above described boron compound is continuously fed in a large scale to and reacted with a transition metal compound such as a metallocene complex, non-metallocene complex or the like, and a reactors for olefin polymerization. Among them, it is applied suitably from the industrial viewpoint to reactors for olefin polymerization to which the above described boron compound needs to be continuously fed for a long period.
The reactors for olefin polymerization include, for example, reactors used for solvent polymerization or slurry polymerization in which an aliphatic hydrocarbon such as butane, pentane, hexane, heptane, octane or the like is used as the solvent, high-pressure ionic polymerization carried out without solvent and under high-temperature and high-pressure, gas phase polymerization carried out in a gaseous monomer and the like.
Preferred one is a reactor for olefin polymerization by high-temperature solution polymerization in which the polymerization of olefins is carried out using a solvent such as cyclohexane or the like under conditions of 120-250xc2x0 C. and 5-50 kg/cm2 at which polymers are melted or by high-pressure ionic polymerization in which the polymerization is carried out under a pressure of at least 300 kg/cm2G and a temperature of at least 130xc2x0 C. More suitably, it can be applied to a reactor for olefin polymerization by high-pressure ionic polymerization in which feed needs to be continued for a long period, and the advantage of the present invention is especially great.
In the present invention, when the above described boron compound are continuously fed to a reactor in the state suspended or slurried in a solvent, the feed to the reactor is suitably effected using a pump through a pipeline.
In the present invention, while shape, particle property, particle diameter, distribution of particle size and the like of the above described boron compounds are not particularly limited, it is preferred that the particle diameter is smaller because the possibility of blockade in a feeding apparatus (for example, pump) is reduced and the sedimentation velocity in the pipeline tends to become lower.
Such boron compounds include the above described boron compounds in the form of fine particles having a maximum particle diameter of 50 xcexcm or less. Such boron compounds in the form of fine particles allow steady feed by and stable operation of the feeding apparatus, without any troubles such as blockade in the feeding apparatus (for example, pump) in case where used in the industrial production conducted in a large scale, by using, for example, in the suspended or slurried state or in the powdery state rather than the dissolved state, when, for example, used as a catalyst component for olefin polymerization. The maximum particle diameter of such boron compounds in the form of fine particles is preferably 30 xcexcm or less, more preferably 10 xcexcm or less and in particular preferably 5 xcexcm or less.
A method for producing such boron compounds in the form of fine particles is not particularly limited insofar as it allows the maximum particle diameter of the boron compounds to be 50 xcexcm or less, and there can be illustrated, for example, a method in which the above described boron compound is dissolved in an aromatic hydrocarbon solvent and then precipitated in an aliphatic hydrocarbon solvent, or the like.
Specific examples of said aromatic hydrocarbon solvent include benzene, toluene, ethylbenzene, propylbenzene, isopropylbenzene, butylbenzene, isobutylbenzene, o-xylene, m-xylene, p-xylene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, fluorobenzene, o-difluorobenzene, m-difluorobenzene, p-difluorobenzene, 1,2,3-trifluorobenzene, 1,2,4-trifluorobenzene, 1,3,5-trifluorobenzene, 1,2,3,4-tetrafluorobenzene, 1,2,4,5-tetrafluorobenzene, pentafluorobenzene, hexafluorobenzene, chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, 1,2,3-trichlorobenzene, 1,2,4-trichlorobenzene, 1,3,5-trichlorobenzene, 1,2,3,4-tetrachlorobenzene, 1,2,4,5-tetrachlorobenzene, pentachlorobenzene, hexachlorobenzene, bromobenzene, o-dibromobenzene, m-dibromobenzene, p-dibromobenzene, 1,2,3-tribromobenzene, 1,2,4-tribromobenzene, 1,3,5-tribromobenzene, 1,2,3,4-tetrabromobenzene, 1,2,4,5-tetrabromobenzene, pentabromobenzene, hexabromobenzene and the like. Preferred one is toluene.
Usually, it is desirable that the concentration of the solution of said boron compound is at the solubility for saturation. It is also preferable to set the temperature of the solution higher in order to increase the concentration.
Specific examples of the above described aliphatic hydrocarbon solvent include pentane, 2-methylpentane, 3-methylpentane, cyclopentane, methylcyclopentane, hexane, 2-methylhexane, 3-methylhexane, cyclohexane, methylcyclohexane, heptane, 2-methylheptane, 3-methylheptane, 4-methylheptane, cycloheptane, octane, nonane, decane, a petroleum ether (petroleum benzine), a mineral oil (paraffin oil), ligroin (mineral spirit) and the like, and hexane or heptane is preferred.
The method for precipitating the boron compound from an aromatic hydrocarbon solution to an aliphatic hydrocarbon solvent includes, generally, a method in which the solution is added dropwise to a large amount of stirred aliphatic hydrocarbon solvent.
The rate of dropwise addition can be set at any value according to the amount of the solution.
The method of stirring during the dropwise addition includes a method in which the known stirring blade is used for stirring, a method in which one of various dispersing instruments excellent in dispersing efficiency (for example, homogenizer, line mixer, ultrasonic radiator and the like), and any known method can be applied without particular limitation.
Depending on particular case, the stirring may be completely omitted.
The amount of the aliphatic hydrocarbon solvent to be used is not particularly limited and any amount of the aliphatic hydrocarbon solvent required to precipitate the boron compounds dissolved in an aromatic hydrocarbon solvent may be used. Specifically, the aliphatic hydrocarbon solvent may be used in an amount 0.1 to 1,000 times the volume or weight of the solution of the boron compound in the aromatic hydrocarbon solvent. More preferably, it is used in an amount 1 to 100 times, further preferably 1 to 10 times.
Sometimes, the obtained boron compound in the form of fine particles is washed further with an aliphatic hydrocarbon solvent.
The boron compound in the form of fine particles obtained in the above described manner can be those having a maximum particle diameter of 10 xcexcm or less, and is substantially free from the aromatic hydrocarbon solvent such as toluene or the like.
And, as the method for producing such a boron compound in the form of fine particles, there is given a method in which it is converted into fine particles having the maximum particle diameter of 50 xcexcm or less by pulverization.
The method for pulverization is not particularly limited insofar as it is a pulverizing method allowing to pulverize said boron compounds into those of the maximum particle diameter of 50 xcexcm or less, and may be any one of batch pulverizing method and continuous pulverizing method using routine pulverizing machine, or closed circuit pulverization method in which classification is simultaneously performed.
Specific examples of such pulverizing machine include jaw crusher, gyratory crusher, hammer crusher, roll crusher, ring roller mill, ball bearing mill, bowl mill, edge runner, stamp mill, hammer mill, cage mill, pin mill, disintegrator, dismembrator, cutter mill, feather mill, oscillating rod mill, aerofall mill, cascade mill, hard shell mill, turbo-mill, microcyclomate, hurricane mill, pot mill, compound mill, compartment mill, conical ball mill, supercritical mill, radial mill, tower mill, circular vibration mill, disk mill, high swing ball mill, centrifugal ball mill, sand grinder, atomizer, pulverizer, supermicron mill, jet mill, colloid mill, mortar and the like.
The method for pulverization may either be a dry pulverizing method which is carried out with the boron compound in dry state or wet pulverizing method which is carried out using a solvent or dispersing medium depending on the kind of pulverizing machine. A preferable solvent or dispersing medium used in the wet pulverizing method is an aliphatic hydrocarbon solvent.
As the aliphatic hydrocarbon solvent, similar one to the already described aliphatic hydrocarbon solvent can be used.
The method for controlling the particle diameter of the boron compound by pulverization is not particularly limited in either a dry pulverizing method and a wet pulverizing method, and may be one which allows pulverization by selecting conditions for pulverization such that the maximum particle diameter of the boron compounds is 50 xcexcm or less. The conditions for pulverization include, for example, pulverization time, pulverization temperature, number of vibration of pulverizing machine, number of rotation, flow rate of gas or liquid applied to pulverizing machine, flow velocity, slurry concentration of slurry of the boron compounds when wet pulverization is conducted, and the like, but the conditions are not limited to them. Similarly, by selecting conditions for pulverization, the maximum particle diameter of the boron compounds can be controlled to 30 xcexcm or less, 10 xcexcm or less or 5 xcexcm or less.
The pulverization time may be set several minutes or more and there is no particular upper limit. The longer the pulverization time is, the smaller the particle diameter of the boron compounds becomes and the smaller the maximum particle diameter becomes. However, when the pulverization time exceeds a certain length, the particle diameter converges and no further change is observed, and therefore, the pulverization may no longer be continued for further time when the particle diameter is considered to attain convergence, and the time may be set within a range, for example, of 10 minutes to 30 days.
The pulverization temperature is not particularly limited, and while some times the temperature of the boron compounds may rise by pulverizing, allowable temperature of the boron compounds is between xe2x88x9210xc2x0 C. and up to the melting point of the boron compounds. Preferably, the temperature is 0 to 100xc2x0 C. and more preferably 0 to 50xc2x0 C.
When, in the kinds of the pulverizing machine, a pulverizing machine in which the pulverization is performed by giving vibration, for example, ball mill pulverizing machine, is used, one of conditions is the frequency of vibration of the container. The frequency of vibration is again not particularly limited and may be set depending on the performance of the pulverizing machine. For example, the frequency may be in the range of 100 times/minute to 100,000 times/minute When, in the kinds of the pulverizing machine, a pulverizing machine in which the pulverization is performed by using revolving hammers, for example hammer mill pulverizing machine, is used, one of conditions is the number of revolution of the hammer. The number of revolution is not particularly limited and may be set depending on the performance of the pulverizing machine, and for example, the frequency may be in the range of 100 times/minute to 100,000 times/minute.
When, in the kind of the pulverizing machine, a pulverizing machine in which the pulverization is performed by collision with each other of the substance in the steam of gas or liquid, for example jet mill pulverizing machine, the flow rate and the flow velocity of the gas or liquid used are not particularly limited, and the flow rate and the flow velocity can be anyone that allows to make the maximum particle diameter of the boron compounds of 50 xcexcm or less: the flow rate may be, for example, within a range of 0.1 liter/second to 1,000 liter/second, and the flow velocity may be, for example, within a range of 0.1 meter/second to 1,000 meter/second.
The slurry concentration of a slurry of the boron compounds in the wet pulverization is not particularly limited, and the slurry concentration can be anyone that allows to make the maximum particle diameter of the boron compounds of 50 xcexcm or less. The concentration may be, for example, 0.01 gram/liter to 1,000 grams/liter, preferably 0.1 gram/liter to 500 grams/liter and more preferably 1 gram/liter to 300 grams/liter.
The stable operation of and steady feed by the feeding apparatus can be realized by feeding the boron compound in the form of fine particles produced as above by the method feeding to a reactor in the state slurried in a solvent or by the method feeding in the state of powders. When used in the polymerization of olefins, the solvent usually used in the polymerization may be used as a solvent for slurrying, and there are illustrated aliphatic hydrocarbon solvents such as pentane, hexane, heptane, octane and the like, and unless the use does not cause problems, aromatic hydrocarbon solvents such as benzene, toluene, xylene and the like and halogenated hydrocarbon solvents such as chloroform, dichloromethane and the like, or others. When the boron compound in the form of fine particles is produced by wet pulverization, the solvent or dispersing medium for the slurry may be the used one.
When the feeding method of the present invention is
When the feeding method of the present invention is adopted in an apparatus for preparing a catalyst for olefin polymerization or in a reactor for olefin polymerization, or when the boron compound in the form of fine particles is used as a catalyst component for olefin polymerization, the catalyst for olefin polymerization includes a catalyst for olefin polymerization obtainable by using (A) a transition metal compound and (B) the above described boron compounds, or a catalyst for olefin polymerization obtainable by using (A) a transition metal compound, (B) the above described boron compounds and (C) an organoaluminum compound.
As the transition metal compound (A) herein, there can be used various compounds exhibiting activity for polymerization of olefins, and examples include metallocene complex and non-metallocene complex. Specific examples include biscyclopentadienyl zirconium dichloride, bis(methylcyclopentadienyl) zirconium dichloride, bis(n-butylcyclopentadienyl) zirconium dichloride, bis(tert-butylcyclopentadienyl) zirconium dichloride, bis(pentamethylcyclopentadienyl) zirconium dichloride, bis(trimethylsilylcyclopentadienyl) zirconium dichloride, ethylenebisindenyl zirconium dichloride, ethylenebis(4,5,6,7-tetrahydroindenyl) zirconium dichloride, dimethylsilylbisindenyl zirconium dichloride, dimethylsilylbis(4,5,6,7-tetrahydroindenyl zirconium dichloride, dimethylsilylbis(2,4-dimethylcyclopentadienyl) zirconium dichloride, zirconium dichloride, dimethylmethylene(cyclopentadienyl) (fluorenyl) zirconium dichloride, diphenylmethylene(cyclopentadienyl) (fluorenyl) zirconium dichloride, dimethylsilyl(tetramethylcyclopentadienyl) (tert-butylamido) zirconium dichloride, dimethylsilyl(tetramethylcyclopentadienyl) (3-tert-butyl-5-methyl-2-phenoxy) zirconium dichloride and the like, and compounds wherein zirconium in these compounds is changed to titanium, and further, compounds wherein dichloride in these compounds including the latter is changed to dimethyl or dibenzyl. Similarly, other examples include N,Nxe2x80x2-bis(2,6-diisopropylphenyl)-1,2-dimethylethylenediimino nickel dibromide, N,Nxe2x80x2-bis(2,6-diisopropylphenyl)-1,2-dimethylethylenediimino palladium dibromide and the like.
As the organoaluminum compound (C), there can be used compounds having a carbon-aluminum bond in the molecule and generally used in the field of polymerization of olefins. Specific examples include trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, methyl aluminoxane, isobutyl aluminoxane and the like.
As to the amounts to be used of respective catalyst components, it is desirable that respective components are used in a range of 0.1 to 10,000, preferably 5 to 2,000, in molar ratio of compound (C)/compound (A), and 0.01 to 100, preferably 0.5 to 10, in molar ratio of compound (B)/compound (A).
As monomers applicable to polymerization, any olefins having 2-20 carbon atoms can be used and two or more monomers can simultaneously be used. Specific examples of such olefins include linear olefins such as ethylene, propylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, nonene-1, decene-1 and the like, branched olefins such as 3-methylbutene-1, 3-methylpentene-1, 4-methylpentene-1, 2-methylpentene-1 and the like, and should not limited to the above described compounds. Specific examples of combination of monomers for copolymerization include ethylene and propylene, ethylene and butene-1, ethylene and hexene-1, ethylene and octene-1, propylene and butene-1 and the like, and should not limited to the above described combinations.